It should do the trick if it doesn't try to heat the decal up with hair drier or (as I was advised) little piece of cloth soaked in realy warm watter (the hotest your hand can handle). As for allready applyed decals soak them with Micro set (blue one) and leave it for few minutes then put Micro sol (red one) and heat it with hair drier. Never tried but it should work even on decals that are allready in place. You won't be able to move them thou and be very carfull not to rip them.
So red bottle is for really curved surfaces and those with lot of details and blue one is for general use.
If you are able to get, I have heard that Mr. Softener from Gunze is very good for this also (but haven't tried it).